(A) Field of the Invention
The present invention relates to a stacked capacitor and method for preparing the same, and more particularly, to a stacked capacitor having interdigital electrodes and method for preparing the same.
(B) Description of the Related Art
DRAM is a widely used integrated circuit device. With the development of the semiconductor industry, there is an increasing demand for DRAM with higher storage capacity. The memory cell of DRAM consists of a Metal-Oxide-Semiconductor (MOS) transistor and a capacitor electrically connected to each other. The capacitor functions to store the electric charge representing data, and high capacitance is necessary to prevent the data from being lost due to discharge. The method to increase electric charge storing capacity of the capacitor can be achieved by increasing the dielectric constant of the dielectric material and reducing the thickness of the dielectric material used in the capacitor, as well as increasing surface area of the capacitor. However, with the advancement of semiconductor technology proceeds into sub-micron and deep sub-micron, the traditional fabrication process for preparing the capacitor is no longer applicable. Consequently, researchers are trying to develop dielectric material with a higher dielectric constant and to increase surface area of the capacitor so as to increase the capacitance.